An investigation into the 2015 death of Brisbane schoolgirl Tiahleigh Palmer culminated on Tuesday with Queensland police charging Palmer's foster father with murder and arresting her foster brother for alleged incest.

Police confirmed Rick Thorburn, 56, was charged with the 12-year-old's murder at 2pm Tuesday and hours later confirmed her 19-year-old foster brother had been arrested for a number of offences, including perjury and incest.

No charges against the 19-year-old have been laid yet, while his mother and brother also remain with authorities to assist with police enquiries.

Tiahleigh Palmer went missing late last year and her biological mother has been persistently fighting to find out what happened to her daughter, whose body was found on the banks of a Queensland river.

So here's what you need to know about the 11-month investigation which has just had a major breakthrough.

When did Tiahleigh Palmer go missing?

Tiahleigh Palmer was reported missing on October 30 last year.

Palmer was last seen after being dropped to Marsden State High School at about 8.10am that morning. However she was not reported as having shown up to class.

Six days later -- on November 5 -- the Brisbane schoolgirl's body was found on banks of the Pimpana River.